Trike Build - Gear ratios and Clutch help

[BigKid90]

Hi all,

I've almost got a roller for my trike build, which I hope to finish this week!

I've taken a lot of inspiration from the 'The Garage Vlog' Trikes. You can get an idea of what I'm going for HERE

I'm stuck when it comes to gearing, as I'm not experienced in this at all. The TGV guys use a torque convertor, and I'm debating whether I need one or whether to run a centrifugal clutch. Any suggestions on a build like this?

I also don't know what a reasonable gear ratio for something like this would be. They use a 48-tooth rear sprocket which I cannot find anywhere, so trying to understand what alternatives I can find using kart parts, or potentially mini-bike parts.

It's really quite hard to source parts outside of the US and its mostly kart spares here in the UK, hence some of the conflict in what route to go down.

Interested to see what you guys think.

Thanks

 

[redflash]

optimum is 1 to 6....meaning 10 tooth on the torque converter and 60 tooth on the axle. Then again what surface are you riding on dirt/asphalt?
Also what weight is the machine with your butt on it, also what speed do you wish to attempt ? all things that play into ratio.

Da redflash

 

[BigKid90]

optimum is 1 to 6....meaning 10 tooth on the torque converter and 60 tooth on the axle. Then again what surface are you riding on dirt/asphalt?
Also what weight is the machine with your butt on it, also what speed do you wish to attempt ? all things that play into ratio.

Da redflash

Thanks!

It will be a combo of dirt and asphalt, but primarily asphalt.

I feel it'll probably be more fun being torquey at low speeds, popping wheelies etc than a particularly high top speed.

It's going to tip the scale over 300lbs with the bike and rider once all is said and done.

 

[panchothedog]

You want kart stuff for your rear axle because it much more resembles the back of a kart as compared to a bike. Do like Flash recommends, 60 tooth on the axle and 10 tooth on the torque converter. You will have LOTS of good low end
torque but with the shifting ability some top speed when you want it. Don't go
The centrifugal clutch rout, you will be disappointed.

 

[BigKid90]

You want kart stuff for your rear axle because it much more resembles the back of a kart as compared to a bike. Do like Flash recommends, 60 tooth on the axle and 10 tooth on the torque converter. You will have LOTS of good low end
torque but with the shifting ability some top speed when you want it. Don't go
The centrifugal clutch rout, you will be disappointed.

Thanks.

I’ve now purchased the torque converter as advised. It had both a 10T 428 pitch sprocket and a 12 Tooth 35 pitch sprocket.

Next challenge is finding a suitable sprocket and carrier combo for the rear axle. I’m having trouble with that already. I have a sprocket carrier for 219 pitch kart sprockets but unsure if that’ll work?

 

[Willie1]

You will need to decide if you want a "live" rear axle, which is just a solid axle, or one with a differential, which will help it turn better.

 

[BigKid90]

You will need to decide if you want a "live" rear axle, which is just a solid axle, or one with a differential, which will help it turn better.

I’ve got a rear axle mounted in some carriers, with a brake disc etc, so sprockets and a hub are the final parts before disassembly and paint

 

[BigKid90]

Should I switch from a 428 setup to a 219, and replace the torque converter sprocket with a 219 equivalent?

I might need to go for a 12T and 72T in the rear, or similar

 

[panchothedog]

No. Stay with the 428. It is the most common and will be the easiest to find parts for should the need arise. What is the diameter of your rear axle ?
look for a new carrier or hub with a corresponding 60 tooth. Every big kart supply shop carries them in at least 2 or 3 different diameters. Depending on rear tire size a 72 tooth might give you clearance problems.

 

[Willie1]

I'm not familiar with a 219 pitch chain.
Also would like to know what engine you plan on using before I can make an informed opinion as to chain requirement.

 

[madprofessor]

Unihub - Sprocket Hub | AZ2556 | Azusa 2556 | BMI Karts And Parts
#35 Split Sprocket | 6335** | BMI Karts And Parts
1" Bore Double Split Shaft Collar Black Oxide Set Screw Style (4 PCS) (jeremywellindustry.com)

NOTE: The #35 sprocket (3/8") example above is only because it's easy to find for me. You'll have to hunt hard for the larger 1/2" parts. Reference the chart below...............

Chain for Go Kart, Mini Bike | GoKarts USA®

 

[Willie1]

Unihub - Sprocket Hub | AZ2556 | Azusa 2556 | BMI Karts And Parts
#35 Split Sprocket | 6335** | BMI Karts And Parts
1" Bore Double Split Shaft Collar Black Oxide Set Screw Style (4 PCS) (jeremywellindustry.com)

NOTE: The #35 sprocket (3/8") example above is only because it's easy to find for me. You'll have to hunt hard for the larger 1/2" parts. Reference the chart below...............

Chain for Go Kart, Mini Bike | GoKarts USA®

Haven't heard yet what engine he is going to use. Realistically a quality #35 chain is probably all he would need.
Sometimes having more clearance under the sprocket is more important than the brute strength of a larger chain.

 

[BigKid90]

I’ll reply here generally rather than to the specific comments above.

I’m using a GX200 with a couple of upgrades such as jetting, 18lb valve springs,
valve lapping, cut valve seats, debaffled exhaust etc. It’s running around 9hp & goes to about 6500rpm.

I’m running a 1” axle, but struggling to find a 428 sprocket and carrier to match. These are literally the last of the parts needed

 

[Willie1]

I’m running a 1” axle, but struggling to find a 428 sprocket and carrier to match. These are literally the last of the parts needed

Are you sure it's a 428 and not a #40? Most of the kits have #35 and #40 sprockets included.
At your power level you could use either, and as I said you might like the extra ground clearance using a #35.
It's fairly easy to get sprockets and adapters for 1" axles for either.

 

[BigKid90]

Are you sure it's a 428 and not a #40? Most of the kits have #35 and #40 sprockets included.
At your power level you could use either, and as I said you might like the extra ground clearance using a #35.
It's fairly easy to get sprockets and adapters for 1" axles for either.

Apparantly so, 428 10T sprocket.

I seem to be able to find sprockets or hubs, but not a combination that will work together.

The carrier I have at present is this: https://www.okeparts.com/collection...o-kart-sprocket-carrier-for-25mm-go-kart-axle

However struggling to find 428 sprockets with that PCD pattern and hole size.

May just be a UK thing…

 

[BigKid90]

UPDATE: I can get sprockets in the 46-50 range, would a 50T suffice?

 

[mmhmmtellyuwhut]

Hi all,

I've almost got a roller for my trike build, which I hope to finish this week!

I've taken a lot of inspiration from the 'The Garage Vlog' Trikes. You can get an idea of what I'm going for HERE

I'm stuck when it comes to gearing, as I'm not experienced in this at all. The TGV guys use a torque convertor, and I'm debating whether I need one or whether to run a centrifugal clutch. Any suggestions on a build like this?

I also don't know what a reasonable gear ratio for something like this would be. They use a 48-tooth rear sprocket which I cannot find anywhere, so trying to understand what alternatives I can find using kart parts, or potentially mini-bike parts.

It's really quite hard to source parts outside of the US and its mostly kart spares here in the UK, hence some of the conflict in what route to go down.

Interested to see what you guys think.

Thanks

what size tires. and heads up if you put 50%weight on rear youl never turn , i built one assuming the tire would skip or drag or i would lean and help it but nope not even a little of any of that , it hooked and went straight always .and the gearing on mine was eventually about 20:1wich seamed pretty tall still

 

[mmhmmtellyuwhut]

what size tire ?

UPDATE: I can get sprockets in the 46-50 range, would a 50T suffice?

 

[JimD]

Big problem with a #428 sprocket you can ONLY use the 428 chain. The roller in the #428 chain is too large to fit either the #41 or the #40 sprockets. It takes a special hob to cut the teeth in the sprocket for the #428 chain. Motorcycles use the larger chain but finding sprockets for it that fit go karts or mini-bikes are difficult to find in the US. It is more common in the UK to find that size chain on fun karts and rental concession karts.

 

[Willie1]

Big problem with a #428 sprocket you can ONLY use the 428 chain. The roller in the #428 chain is too large to fit either the #41 or the #40 sprockets. It takes a special hob to cut the teeth in the sprocket for the #428 chain. Motorcycles use the larger chain but finding sprockets for it that fit go karts or mini-bikes are difficult to find in the US. It is more common in the UK to find that size chain on fun karts and rental concession karts.

One of the big reasons I suggested using #35 chain and sprockets.